THE STORY OF ELECTRICITY BY JOHN MUNRO AUTHOR OF ELECTRICITY AND ITS USES, PIONEERS OF ELECTRICITY, HEROES OF THE TELEGRAPH, ETC., AND JOINT AUTHOR OF MUNRO AND JAMIESON'S POCKET-BOOK OF ELECTRICAL RULES AND TABLES PREFACE. A work on electricity needs little recommendation to stimulate the interest of the general reader. Electricity in its manifold applications is so large a factor in the comfort and convenience of our daily life, so essential to the industrial organization which embraces every dweller in a civilized land, so important in the development and extension of civilization itself, that a knowledge of its principles and the means through which they are directed to the service of mankind should be a part of the mental equipment of everyone who pretends to education in its truest sense. Let anyone stop to consider how he individually would be affected if all electrical service were suddenly to cease, and he cannot fail to appreciate the claims of electricity to attentive study. The purpose of this little book is to present the essential facts of electrical science in a popular and interesting way, as befits the scheme of the series to which it belongs. Electrical phenomena have been observed since the first man viewed one of the most spectacular and magnificent of them all in the thunderstorm, but the services of electricity which we enjoy are the product solely of scientific achievement in the nineteenth century. It is to these services that the main part of the following discussion is devoted. The introductory chapters deal with various sources of electrical energy, in friction, chemical action, heat and magnetism. The rest of the book describes the applications of electricity in electroplating, communication by telegraph, telephone, and wireless telegraphy, the production of light and heat, the transmission of power, transportation over rails and in vehicles, and the multitude of other uses. July, 1915. PUBLISHERS' NOTE. For our edition of this work the terminology has been altered to conform with American usage, some new matter has been added, and a few of the cuts have been changed and some new ones introduced, in order to adapt the book fully to the practical requirements of American readers. CONTENTS. I. THE ELECTRICITY OF FRICTION II. THE ELECTRICITY OF CHEMISTRY III. THE ELECTRICITY OF HEAT IV. THE ELECTRICITY OF MAGNETISM V. ELECTROLYSIS VI. THE TELEGRAPH AND TELEPHONE VII. ELECTRIC LIGHT AND HEAT VIII. ELECTRIC POWER IX. MINOR USES OF ELECTRICITY X. THE WIRELESS TELEGRAPH XI. ELECTRO-CHEMISTRY AND ELECTRO-METALLURGY XII. ELECTRIC RAILWAYS APPENDIX THE STORY OF ELECTRICITY. CHAPTER I. THE ELECTRICITY OF FRICTION.